Stabilization of halobutenes



Patented Dec. 5, 1944 STABILIZATION 0F HALOBUTENES Rupert 0. Morris, Berkeley, and Edward O. Shokal, Oakland, Calif., assignors to Shell Development Company, San Francisco, Calii'., a corporation of Delaware No Drawing. Application April 19, 1943, Serial No. 483,706

16 Claims. (Cl. 260-6525) This invention relates to a method for preventing or inhibiting the decomposition of the halobutenes which contain a halogen atom linked to an unsaturated carbon atom under conditions encountered during their transportation and storage. The invention also pertains to the stabilized halobutene compositions resulting from the application of such method.

The marked tendency of the halobutenes which contain a halogen atom linked to an unsaturated carbon atom, particularly 2-chlorobutene-2, to undergo decomposition during shipment and storage, particularly in the presence of small amounts of water, has been long recognized, While in general this tendency is most pronounced in metal containers, as copper or fermginous containers, in many cases extensive decomposition may occur in glass as well. The decomposition whether occurring in glass or in metal imparts undesirable characteristics as bad odor and objectionable color to the packaged liquid which adversely afiect its salability. In the case of metal containers the problem may be two-fold since substantial corrosion of the walls of the container may result.

The various inhibitors which have heretofore been proposed to suppress the deterioration of organic halides during shipment and storage while in some instances fairly effective are in general unsuitable for the stabilization of the halobutenes which contain a halogen atom linked to an unsaturated carbon atom either because of the large quantity of inhibitor which must be added or because of difficulties encountered in separating the inhibitor, when necessary, after it has served its purpose.

It has now been found that th deterioration of the halobutenes which contain a halogen atom linked to an unsaturated carbon atom, and particularly those, such as Z-chlorobutene-Z, wherein the olefinic linkage is in the 2-position, under ordinary conditions of shipment and storage, may be efiectively suppressed by mixing therewith a small amount of an epoxide compound. Representative epoxide compounds include the alkylene oxides such as ethylene oxide, propylene oxide, butene-l oxide, butene-Z oxide, isobutylene oxide, trimethylene oxide, butadiene monoxide, butadiene dioxide, lsopropyl ethyleneoxide, alphamethyl-alpha-ethyl-ethylene oxide, cyclopentylenc oxide, styrene oxide, cyclohexenoxide, 3,4- epoxyl-methyl-cyclohexane, 2,3-epoxy decalin, plnene oxide, benzyl ethylene oxide, etc. as well as substituted alkylene oxides which contain various substltuent groups in addition to the The method of stabilizing halobutenes provided by the invention is applicable irrespective of the type of container in which the liquid is packaged, but is especially valuable in connection with the shipment and/or storage of these organic halides in ferruginous containers.

The invention is applicable to the stabilization of the halobutenes which contain a halogen atom linked to an unsaturated carbon atom. The olefinic linkage in the halobuten may be between the first and second carbon atoms (1 or alpha position) or it may be between the second and third carbon atoms (2 or beta position). The invention is of particular value and usefulness as applied to the stabilization of 2-chlor'obutene-2 and the other Z-halobutenes wherein the olefinic linkage is in the 2 position. Such halobutenes may contain one or a plurality of halogen atoms linked to the unsaturated carbon atom or carbon atoms,

bromobutene-Z,

and one or a plurality of halogen atoms may also be linked to saturated carbon atoms. genatom or atoms present in the halobutene may be fluorine, chlorine, bromine or iodine; Representative halobutenes which may be stabilized in accordance with the invention are: 2-chlorobutene-2, 2-bromobutene-2, 2-iodobutene-2, 1,2- dichlorobutene-Z, 2,3-dichlorobutene-2, 2,3-di- 1,2,3-trichlorobutene-2, 1,2,4- trlchlorobutene-2, 2-chlorobutene-1, Z-bromobutene-l, l-chlorobutene-l, 2,3-dlchlorobutene-1, l-bromobutene-l, 2-iodobutene-1, 1,2-dich1orobutene-l and 1,2,3-trichlorobutene-1.

Although the proportion or amount of inhibitor which is added to suppress the decomposition of the halobutenes according to the invention and to produce the novel compositions of matter encompassed thereby may vary within wide limits, it is preferred to add the smallest efiective epoxide group like the epihalohydrlns such as 55 amount. This is usually between about 0.1% and The haloabout 5% by volume, depending inter alia upon the degree of instability of the particular halide being prepared for shipment or storage, the period over which the halide must be preserved, and the particular inhibitor which is being used.

The present invention has been found especial 1y useful as a means of stabilizing z-chlorobutene-2, large amounts of which are produced as a by-product during the synthesis of butadiene from dichlorobutane. 2-chlorobutene-2 is useful, for example, as an ingredient in paint removers and as a degreasing and extraction solvent.

when it is first recovered or prepared z-chlorobutene-2 usually is clear and substantially waterwhite, and it has a sweet odor and does not give off hydrogen chloride fumes. However,- when stored for even a relatively short period of time in glass containers the liquid develops a deep yellow color and has a sharp disagreeable odor.- Storage in ferruginous containers displays its decomposition even more prominently, i. e, it becomes nea-rly black and a tarry deposit forms on the sides of the container. 1

The suitability of several of the inhibitors provided by-the invention in the stabilization of 2- chlorobutene-2 is illustrated by the following examples, it being understood that the practice of the invention is not limited to the stabilization of this particular halobutene.

Example I Example 11 1% by volume of propylene oxide was added to a bottle of 2-chlorobutene-2 in which a strip of drum iron had been immersed. At the end of 27 days the Gardner scale reading on the liquid was 1 and the strip was only very slightly affected. (On the Gardner scale No. 1 is waterwhite, No. 15 is dark brown.)

Example III A standard one-gallon steel shipping drum as filled about /2 to A; full of by-product z-ohlorobutene-2 to which had been added about 1% by volume of epichlorhydrin. The drum was allowed to remain exposed to the elements for 10 months, at the endof which time examination was made of container and its contents. The liquid poured from th drum absolutely clear and there was only a very light deposit on the walls of the drum. When a sample of the stored liquid was tested for color by the Gardner scale the reading was less than 1.

We claim as our invention:

1. The method of stabilizing 2-chlorobutene-2 which comprises adding thereto about 1% to about 5% by volume of a glycidyl ether.

2. The method of stabilizing 2-chlorobutene-2- which comprises adding thereto about 1% by volume of propylene oxide.

3. The method of stabilizing 2-chlorobutene-2 which comprises adding thereto about 1% by volume of an alkylene oxide.

4. The method of stabilizing 2-chlorobutene-2 which comprises adding thereto about 1% by volume of epichlorhydrin.

5. The method of preventing the decomposition of 2-chlorobutene-2 which comprises adding thereto a stabilizing amount of an epoxide compound.

6. As a composition of matter 2-chlorobutene-2 containing a stabilizing quantity of a glycidyl ether dissolved therein.

'7. As a composition of matter 2-chlorobutene-2 containing a stabilizing quantity of propylene oxide dissolved therein.

8. As a composition of matter 2-chlorobutene-2 containing a stabilizing quantity of an alkylene oxide dissolved therein. Y

9. As a composition of matter 2-chlorobutene-2 containing a stabilizing quantity of epichlorhydrin dissolved therein.

10. As a composition of matter 2-chlorobutene-2 containing a stabilizing quantity ofan epoxide compound dissolved therein.

11. The method of preventing the decomposition of a 2-halobutene in which the oleflnic linkage is in the 2-position which comprises adding thereto a stabilizing amount of an epoxide compound.

12. As a composition of matter a z-halobutene in which the oleflnic linkage is in the 2-position having dissolved therein a stabilizing quantity of an epoxide compound.

13. The method of preventing the decomposition ofa mono halobutene in which the halogen atom is linked to an unsaturated carbon atom which comprises adding thereto a stabilizing amount of an epoxide compound.

14. A composition of matter comprising a mono halobutene in which the halogen atom is linked to an unsaturated carbon atom and a stabilizing amount of an epoxide compound.

15. The method of preventing the decomposition of a halobutene containing a halogen atom linked to an unsaturated carbon atom which comprises adding thereto a stabilizing amount of an epoxide compound.

16. A composition of matter comprising a halo butene containing a halogen atom linked to an unsaturated carbon atom and a stabilizing amount of an epoxide compound.

RUPERT C. MORRIS. EDWARD C. SHOKAL. 

